Only 2 years of part-time self study? Honestly, you’ve only scratched the surface. Sign up for some Udemy (or other) courses, follow some free tutorials on youtube, join some contests to push and challenge yourself. But giving up so early? Of course you won’t have professional results with only 2 years of part time self study. Some people graduate from 4 years of full-time study and aren’t yet professional quality. Don’t give up so quickly.

Whilst it’s common for an artist to be their own worst critic (and often useful), I think you’re being overly harsh about your work. You have quite a bit of Hand Painted work on your profile, which as an art style is a real labour of love and takes lot of time to master. I see solid progress from your early works up to your latest. Don’t be so hard on yourself for it not being what you want it to be, try to find positives in what you’ve done and start looking at how to improve it in a logical way.

I would say the first step in improving your work is to figure out where it differs from the look you’re aiming for. Not just a simple “it doesnt look as good as X”, but very specific things - my colors seem flatter, my character feels less detailed, my textures feel muddy, my metal doesn’t look like metal, etc, etc. Only in finding the very specific things that you think your work lacks can you look for ways to improve them.

You could find those improvements looking at existing work in screenshots, in games, or from tutorials. Really looking at how others are producing the types of work your striving to make. With hand painted texturing specifically, I would recommend anywhere you can get a real good look at a flat version of just the Albedo texture. Unravelling what is model, what is normal, what is lighting and what is texture can often shed some light on the approach to take.

If you haven’t already, check out https://handpaintersguild.com/ - a really supportive community of hand painting artists. They have a Discord for sharing works, getting feedback and chatting about techniques, as well as a HUGE list of tutorials that will help you along the way!